Field of the Invention
The present invention relates to a heat pump system for a vehicle and, more particularly, to a heat pump system for a vehicle configured for cooling a battery module using a single chiller in which a refrigerant and a coolant are heat exchanged and enhancing heating efficiency using a waste heat source of a motor, an electric/electronic component, and a battery module.
Description of Related Art
In general, air-conditioning devices for a vehicle include an air-conditioner system circulating a refrigerant to heat or cool an indoor area of a vehicle.
Such an air conditioner device, maintaining an appropriate temperature in an indoor area of a vehicle, regardless of a change in an ambient temperature, to maintain an agreeable indoor environment, is configured such that a refrigerant discharged according to driving of a compressor circulates through a condenser, a receiver dryer, an expansion valve, an evaporator, and back to the compressor, and in this process, the indoor area of the vehicle is heated or cooled by heat-exchange based on the evaporator.
That is, in a cooling mode of in the air conditioner device in summer, a high-temperature, high-pressure gaseous refrigerant compressed by the compressor is condensed through the condenser and evaporated in the evaporator through the receiver dryer and the expansion valve to lower an indoor temperature and humidity.
Recently, as an interest in energy efficiency and environmental pollution problem is growing, development of eco-friendly vehicles (or green cars) that may substantially replace internal combustion engine vehicles is required, and such green cars are generally classified as an electric vehicle driven using a fuel cell or electricity as a power source and a hybrid vehicle driven using an engine and a battery.
Among the eco-friendly vehicles, an electric vehicle or a hybrid vehicle does not use a separate heater, unlike an air-conditioning device of a general vehicle, and an air-conditioning device applied to an eco-friendly vehicle is generally called a heat pump system.
In an electric vehicle, driving power is generated by converting chemical reaction energy of oxygen and hydrogen into electric energy, and in this process, thermal energy is generated due to a chemical reaction within a fuel cell, and thus, it is essential to effectively remove generated heat to secure performance of a fuel cell.
Also, in a hybrid vehicle, a motor is driven using a fuel cell or electricity supplied from an electric battery, together with an engine operated by general fuel, to generate driving power, and here, in order to secure performance of the motor, heat generated from the fuel cell, the battery, and the motor is required to be effectively removed.
Thus, in the related art hybrid vehicle or electric vehicle, a cooling device for an electric/electronic component, a heat pump system, and a battery cooling system are required to be configured as separate airtight circuits in order to prevent heating of a battery.
As a result, a size and weight of a cooling module disposed on a front side of a vehicle are increased, and a layout of connection pipes supplying a refrigerant or a coolant to the heat pump system, the cooling device for an electric/electric component, and the battery cooling system from the inside of an engine room is complicated.
Also, since the battery cooling system for warming up or cooling a battery is separately provided according to a state of a vehicle to allow a battery to exhibit optimal performance, a plurality of valves are applied to connect the connection pipes, and noise and vibrations due to frequent opening and closing operations of the valves are transmitted to an indoor area of a vehicle to degrade ride comfort.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.